Brennan

Brennan is the 697th most common surname in the United States, shared by 47,806 people at the 2020 census. That is about one person in 6,252.

By the numbers

People: 47,806
Rank: 697th
How common: 1 in 6,252
Per 100,000: 16.0

Where the name comes from

Origin Irish

From Irish Ó Braonáin (“descendant of Braonán”), a diminutive of braon (“moisture, drop”). Alternatively, from Irish Ó Branáin (“descendant of Branán”), a diminutive of bran (“raven”).

Etymology from Wiktionary, used under CC BY-SA 4.0.

Who bears the name

How people with the surname Brennan described their own race and Hispanic origin at the 2020 census:

White, not Hispanic 91.7%
Hispanic or Latino 3.4%
Two or more races, not Hispanic 2.9%
Asian or Pacific Islander, not Hispanic 0.9%
Black, not Hispanic 0.9%
American Indian or Alaska Native, not Hispanic 0.2%

Notable people called Brennan

Walter Brennan (1894–1974)American actor
Moya Brennan (1952–2026)Irish folk singer, songwriter, harpist, and philanthropist
Eileen Brennan (1932–2013)American actress and singer
John Owen Brennan (born 1955)Director of the Central Intelligence Agency from 2013 to 2017
James Herbert Brennan (1940–2024)Irish writer
Ian Brennan (born 1978)American screenwriter, producer, director and actor
William J. Brennan (1906–1997)U.S. Supreme Court justice from 1956 to 1990
Kim Brennan (born 1985)Australian rower

People named Brennan with articles in the most Wikipedia languages. Data from Wikidata (CC0).

Surnames like Brennan

Also a first name

Brennan has been given to 35,487 American babies as a first name since 1916, peaking in 2009. See it as a given name.

Try it on yourself

Source: US Census Bureau, Frequently Occurring Surnames, 2020. The Census describes the file as the surnames borne by 100 or more people; rarer names are not published. The line is not quite exact, and 617 published names come in under it, the smallest at 92 people. Race and Hispanic origin are self-reported. Rates are worked out against the 298.9 million people the file's own figures are calculated on, which is fewer than the census counted in all: the difference is everyone whose surname was too rare to publish.